304 MORPHOLOGY AND EVOLUTION
Sometimes it is represented by separate filaments running down from the brachial plexus.
The subscapular nerves are from three to five in number. They supply the subscapularis, latissimus dorsi and teres major, but Hepburn (83) states that the circumflex nerve supplies the teres major in the Gorilla.
The median nerve in the Chimpanzee supplies the coraco-brachialis in the upper part of the arm. Just below the end of the elbow it supplies the flexor carpi radialis, flexor sublimis digitorum and both heads of the pronator radii teres. In the forearm lower down it communicates with the ulnar nerve and supplies the flexor sublimis and flexor profundus digitorum. It divides in the palm into outer and inner branches. The former supplies the thenar muscles, first lumbrical and the skin of the adjacent sides of the thumb and index finger. The latter supplies the third and fourth lumbri-cales and the skin of the adjacent sides of the second, third and fourth digits. The nerve to the second and third digits supplies the second lumbrical muscle.
In the Gorilla and Orang the muscular and cutaneous distribution are as in Man.
The ulnar nerve courses as in Man. In the Chimpanzee it supplies the flexor carpi ulnaris and flexor profundus digitorum.
Two inches proximal to the wrist it divides into anterior and posterior divisions. The former supplies the hypothenar muscles, and its cutaneous distribution is as in Man; the latter goes deeply to supply the ..palmar interosseous muscles. A dorsal branch of the main trunk runs to the interosseous muscles, adductores